Note: Descriptions are shown in the official language in which they were submitted.
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1
A FILTER PLATE ASSEMBLY FOR A HORIZONTAL PLATE AND FRAME -TYPE
FILTER, SUCH AS A TOWER PRESS, A FILTER PLATE AND A VAT LINER
FIELD OF THE DISCLOSURE
The present disclosure relates to horizontal plate and frame- type filters,
such as tower
presses, and more particularly to a filter plate assembly for such a filter.
The present
disclosure further concerns a filter plate and a vat liner for such a filter
plate assembly.
BACKGROUND OF THE DISCLOSURE
Conventionally in horizontal filter plate and frame -type filters, such as
tower presses, a
filtrate is collected to a filtrate vat from a filter chamber formed above the
vat. As the filtrate
typically contains small solid particles, the filtrate flow (and a possible
drying air flow) is
abrasive over numerous repeated filtration cycles. To this end, the filtrate
vat has
conventionally been provided as a separate, replaceable component, made of a
material
able to sufficiently withstand wear caused by the abrasive flow. In known
arrangements,
the filtrate vat has been provided as component forming a receptacle for
receiving the
filtrate and has been placed on top of a substantially flat filter plate. When
the filtrate vat
has worn excessively, it is replaced.
However, it has been noticed, that such a wear resistant separate filtrate vat
is prone to
creeping under as it is repetitively compressed over numerous filtration
cycles. Moreover,
it has not been generally considered that changing the material of the
filtrate vat so as to
better resist deformation due to creeping would result in unsatisfactory wear-
resistance
characteristics.
It has also been noted that conventional, separate filtrate vats have faced
issues related
to contamination from the slurry to be filtered and other process fluids.
Particularly, slurry
that has reached the interface between the filter plate and the filtrate vat
may travel
underneath the filtrate vat due to the capillary effect and the repetitive
compression of the
filtration cycles. Such impurities cause a bulge on the otherwise flat filter
plate, thereby
leading to premature wear of the filtrate vat and even breakage thereof.
Moreover, slurry
or other process fluid contamination may seize fasteners used to attach the
filtrate vat to
the filter plate, thereby hindering the maintenance of the associated filter,
such as
replacement of the filtrate vat.
BRIEF DESCRIPTION OF THE DISCLOSURE
An object of the present disclosure is to provide a filter plate assembly, a
filter plate and a
vat liner, which are resistant to both wear and deformation caused by
creeping, while
facilitating maintenance.
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The object of the disclosure is achieved by the filter plate assembly, the
filter plate and the
vat liner which are characterized by what is stated in the independent claims.
The preferred
embodiments of the disclosure are disclosed in the dependent claims.
The disclosure is based on the idea of providing the filtrate vat formed on,
and integral with
the filter plate, in addition to a separate, replaceable vat liner. In this
way, a rigid structure
of the filtrate vat capable of resisting deformation may be achieved, while
the vat liner
separates the filtrate from the filtrate vat and the associated filter plate,
providing wear
resistance and facilitating maintenance.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following the disclosure will be described in greater detail by means
of preferred
embodiments with reference to the accompanying drawings, in which
Fig. 1 illustrates a plan view of a filter plate assembly according to an
embodiment of the
present invention;
Fig. 2 illustrates a cross-sectional cut view along the cut line illustrated
in Fig. 1;
Fig. 3 illustrates a filter plate assembly similar to that of Fig.1, without
outlet pieces, and
equipped with a filtrate vat, as seen as an exploded perspective view;
Fig. 4 illustrates the filter plate assembly of Fig. 3 as seen as a plan view;
Fig. 5 illustrates the filter plate assembly of Fig. 3 as an exploded cross
section cut view
along the dashed line illustrated in Fig. 4;
Fig. 6 illustrates the filter plate assembly of Fig. 3 as a cross section cut
view along the
dashed line illustrated in Fig. 4;
Fig. 7 illustrates the filter plate assembly of Fig. 1, as seen as a semi-
exploded perspective
view;
Fig. 8 illustrates a detailed view of the outlet piece of Fig. 7;
Fig. 9 illustrates the situation of Fig. 8 in a non-exploded view;
Fig. 10 illustrates the filter plate assembly of Fig. 7 as a plan view;
Fig. 11 illustrates an exploded partial cross-sectional cut view of the filter
plate assembly
of Fig 7, along the dashed line illustrated in Fig. 10, and
Fig. 12 illustrates the situation of Fig. 11 in a non-exploded view.
DETAILED DESCRIPTION OF THE DISCLOSURE
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According to a first aspect of the present disclosure, a filter plate assembly
1 for a
horizontal plate and frame -type filter, such as a tower press, is provided.
The filter plate assembly comprises a filter plate 2 having a rigid plate-like
body. The filter
plate 2 has a frame side 2a and a vat side 2b. The frame side 2a is intended
to face
towards a plate frame 9, on which the filter plate is supported, when in use,
whereas the
vat side 2b refers to the side of the filter plate 2, on which a filtrate vat
4 is formed, and is
intended to face towards a filter chamber formed by the filter plate assembly
1 together
with an adjacent filter plate assembly above. When in use, a filter plate
assembly 1 is
separated from an adjacent filter plate assembly above, with which a closed
filter chamber
is formed, with a filter medium (typically a filter cloth), such that slurry
is fed into the filter
chamber of the filter plate assembly 1 above, and filtrate separated from the
slurry by the
cloth is received in the filtrate vat 4 of the filter plate assembly 1 below.
The filter plate 2 comprises, on the chamber 2b side, a border 3 having at
least an inner
lateral wall 3a and an upper surface 3b. The border 3 is elevated for a
distance at least
from a portion of the filter plate 2 delimited within the border 3.
Particularly, the border 3 is
formed integral with the filter plate 2.
Particularly, a filtrate vat 4 is formed by the filter plate 2, such that the
inner lateral wall 3a
of the border forms a lateral wall of the filtrate vat 4, and a portion of the
filter plate delimited
by the border 3 forms a bottom of the filtrate vat 4. That is, a receptacle
for receiving filtrate
is formed by the shape of the filter plate 2 itself.
For example, the filter plate 2 may be provided in accordance with the third
aspect of the
present disclosure.
The filter plate assembly 1 further comprises a vat liner 5 having a sheet-
like body. The
vat liner 5 is nested within the filtrate vat 4 such that the vat liner 5
extends onto the upper
surface 3b of the border 3, so that the filter plate 2 is separated from
filtrate within the
filtrate vat 4 by the vat liner 5, when in use. That is, the vat liner 5
extends along lateral
inner wall 3a of the border 3.
For example, the vat liner 5 may be provided in accordance with the third
aspect of the
present disclosure.
In this way, the filter plate 2 may be constructed so as to provide a rigid
structure forming
the shape of the filtrate vat 4 being able to resist deformation due to
creeping, while the
vat liner 5 shield the filtrate vat 4 from wear caused by abrasion, as
discussed earlier.
Furthermore, as the vat liner 5 is much lighter, as compared to a conventional
separate
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filtrate vat, maintenance is facilitated as manipulating the vat liner 5 is
easier and the whole
filter plate does not ned to be removed from the associated filter apparatus.
Preferably, but not necessarily, the vat liner 5 also extends over the upper
surface 3b of
the border 3.
Most suitably, the filter plate 2 is of a more rigid material 5, and able to
better resist
creeping than the vat liner 5, whereas the vat liner 5 is of a more wear
resistant material
than the filter plate 2.
Examples of such materials of the filter plate 2 include, but are not limited
to, metals, such
as steel, FRP (fibre-reinforce plastics) materials, such as reinforced
composite materials
with a thermoset or thermoplastic matrix, and thermoset materials.
Correspondingly,
examples of such materials of the vat liner 5 include, but are not limited to,
wear resistant
polymers, such as thermoplastics including thermoplastic vulcanizates and
thermoplastics
elastomers, PUR and rubber.
It should be noted that a plate frame 9 for supporting the filter plate 2 may
be included in
the filter plate assembly 1. Alternatively, the filter frame 9 may be provided
as a separate
component or assembly attachable to the filter plate assembly 1.
In an embodiment according to the first aspect of the present disclosure, the
border 3 has
an outer lateral wall 3c, and the vat liner 5 additionally extends onto the
lateral outer wall
3c.
In this kind of arrangement, slurry or other process fluids are less likely to
travel between
the vat liner 5 and the filter plate 5 all the way to the filtrate vat 4 or
even the upper surface
3b of the border 3, where contamination may cause excess wear or even breakage
under
repetitive compression, as discussed above. This facilitates maintenance as
the
maintenance intervals can be extended.
Furthermore, a more rigid structure of the vat liner 5 itself is achieved,
which facilitates
maintenance, as the vat liner 5 deforms less during installation and is easier
to be seated
in the filtrate vat 4.
Most suitably, but not necessarily, the vat liner 5 extends over the outer
lateral wall 3c of
the border 3. This further improves the benefits mentioned above, as slurry or
other
process fluids must travel even further to reach areas where contamination may
cause
issues.
For example, a trough Sc may be formed on the vat liner 5, the through Sc
running along
the perimeter thereof of the vat liner S. Moreover, the border 3 is then
nested within the
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trough 5c, and an inside of the trough 5c is hollow and the border 3 is solid.
This kind of
structure further allows the border formed 3 by the filter plate 2 to be load
bearing against
the forces required to close a filter chamber (i.e. adjacent filter plate
assemblies being
pressed against each other), while the vat liner 5 merely acts as a covering
or coating
separating the filtrate from the filter plate 2. Additionally, the border 3
being seated in the
trough further secures the vat liner to the filter plate 2.
Furthermore, the trough Sc of the vat liner 4 together with the border 3 acts
as a guide rail
during installation of the vat liner 5, thereby facilitating maintenance.
In an embodiment according to the first aspect of the present disclosure, a
gap 3d is
provided on the border 3, such that an outlet opening extending laterally
through the border
3 is formed, thereby providing a fluid drainage route from the filtrate vat 4.
As the drainage route from the filtrate vat 4 runs laterally, maintenance is
facilitated, as the
drainage rout is easily accessible, as compared to a structure in which the
drainage route
runs vertically through the filter plate.
Preferably, but not necessarily, the vat liner 5 is formed so as to extend
into the outlet
opening, and to cover the border 3 adjacent to the outlet opening, such that
the filter plate
2 is separated from filtrate within the outlet opening by the vat liner 5,
when in use. This
further helps prevent contamination of filtrate running through the outlet
opening from
travelling under the vat liner 5.
Preferably, but not necessarily, on the vat side 2b of the filter plate 2, a
recessed portion
2c of the filter plate situated at the outlet opening is recessed with respect
the bottom of
the filtrate vat 4. Moreover, the vat liner 5 is spaced apart from the filter
plate 2 at the
recessed portion 2c in a direction transverse to the general planarity of the
filter plate 2.
In this kind of structure, the vat liner 5 forms an overhang at the outlet
opening, thereby
preventing filtrate contamination from travelling under the vat liner 5,
between the vat liner
5 and the filter plate 2.
Preferably, but not necessarily, the filter plate assembly 1 further comprises
a removably
fixed outlet piece 6 at least partly nested within the outlet opening.
Moreover, the outlet
piece 6 is being arranged such that the fluid drainage route runs
therethrough.
This facilitates maintenance, as the outlet piece 6 can be replaced separately
¨ the outlet
piece is commonly subjected to most wear due abrasion of the filtrate and/or
drying air
flow.
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Suitably, also the outlet piece 6 is of a creeping-resistant material, as
creeping is
particularly prominent at the outlet piece due to the physical discontinuity
in the physical
structure of the filter plate 2. Examples of such materials of the filter
plate 2 include, but
are not limited to, metals, such as steel, FRP (fibre-reinforce plastics)
materials, such as
reinforced composite materials with a thermoset or thermoplastic matrix, and
thermoset
materials.
The outlet piece may suitably be coated with a wear-resistant material to
protect it from
premature wear caused by the filtrate or drying air flow. Examples of such
materials
include, but are not limited to, wear resistant polymers, such as
thermoplastics including
thermoplastic vulcanizates and thermoplastics elastomers, PUR and rubber.
Furthermore, using separate outlet pieces 6 enables using differently
constructed outlet
pieces for different types of filtrates, depending on the application. For
example, the outlet
piece can be shaped so as to optimize the flow characteristics thereof for a
certain kind of
filtrate.
More preferably, the vat liner 5 extends into the outlet piece 6. This
ensures, that the vat
liner 5 can be sealed against outlet piece 6 and minimizes risk of
contamination from
filtrate, slurry, or other process liquids between the vat liner 5 and the
filter plate 2.
Moreover, the one or more outlet pieces 6 can be used to secure the vat liner
5 in place,
such that no other separate fasteners are required. This facilitates
maintenance, as the
fasteners or fixing elements securing the filtrate vat 5 are situated only in
wearing parts
(i.e., the outlet piece 6) which will be replaced along with the filtrate vast
5.
More preferably, the outlet piece 6 comprises a base 7 and a lid 8. The base 7
is at least
partly nested within the recessed portion 2c of the filter plate 2, between
the filter plate 2
and the vat liner 5. The lid 8, in turn, is provided on an opposite side of
the vat liner 5 with
respect to the base.
The base 7 is removably fixed to the remaining filter plate assembly 1, for
example to either
or both of the filter plate 2 and the plate frame 9 supporting the filter
plate, whereas the lid
8 is a removably fixed to the base 7, such that the vat liner 5 is clamped
between the base
7 and the lid 8. In this way, the filtrate drainage route is formed between
the vat liner 5
and the lid 8, while a sealed attachment between the outlet piece 6 and the
vat liner 5 is
achieved, thereby reducing filtrate contamination form travelling under
between the vat
liner 5 and the filter plate 2.
Most preferably, the base 7 of the outlet piece 6 comprises a recessed seat 7a
into which
a gap portion 5d of the vat liner 5, corresponding to a gap 3d of the border
3, is seated.
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Furthermore, the lid 8 comprises a plurality of spaced apart ribs 8a
projecting towards the
recessed seat 7a, such that the vat liner 5 is clamped between the recessed
seat 7a and
the ribs 8a, and is sealed against the recessed seat 7a. The lid 8 extends
over the gap 4
and seals against the border portion 5b of the liner 5 at a position
corresponding to the
upper surface 3b of the border 3. Such an arrangement ensures a secure and
sealed
attachment between the vat liner 5 and the outlet piece 6.
For example, the base 7 may further comprises a recessed chute 7b as a
continuation of
the recessed seat 7a for conducting filtrate out of the outlet piece 6.
Preferably, but not necessarily, the filter plate 2 is of a generally
rectangular shape having
a first flank side 2d and a second flank side 2e parallel to the first flank
side 2d, and a first
end side 2f and a second end side 2g parallel to the first end side 2f.
Moreover, the first
and second end sides 2f, 2g extend in a direction transverse to a direction in
which the
first and second flank sides 2d, 2e extend, and the first and second flank
sides 2d, 2e have
a length greater than that of the first and second end sides 2f, 2g.
In such a case, one or more gaps 3d of the border 3 are formed on either or
both of the
first flank side 2d and the second flank side 2e.
The first and second flank sides 2d, 2e are considered preferred positions for
the gaps 3d,
as this provides easiest access for maintenance (e.g. replacing outlet pieces
6).
More preferably, one or more gaps 3d of the border 3 are formed in a corner
region
between a flank side 2d, 2e and an end side 2f, 2g. The corner regions are
considered
particularly preferred positions for the gaps 3d, as this additionally
provides most secure
attachment of the filtrate vat 5, when it is attached to the filter plate 2
using outlet pieces
6.
More preferably, the filter plate comprises one or more lateral indentation
portion 2i
provided on either or both of the first flank side 2d and the second flank
side 2e. Such
lateral indentation portions 2i are arranged to circumvent suspension elements
and/or
support elements of a filter plate frame 9 on which the filter plate 2 is
supported.
Such an arrangement facilitates maintenance by allowing the filter plate 2 to
be removed
from a plate frame 9 on which it is supported without removing the plate frame
9 from the
filter apparatus.
The filter plate 2 may additionally comprise one or more lateral widening
portions 2j
provided on either or both of the first flank side 2d and the second flank
side 2e. The lateral
widening 2j portions are arranged between lateral indentation portions 2i
adjacent to the
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widening portion 2j. Moreover, the lateral widening portions 2j are arranged
to laterally
overhang a filter plate frame 9 supporting the filter plate 2.
Such an arrangement further facilitates maintenance by allowing the filter
plate 2 to be
lifted at the lateral widening portions 2j.
In an embodiment according to the first aspect of the present disclosure, the
filter plate 2
comprises a plurality of attachment holes 2h running along the periphery of
the filter plate
2 and extending therethrough. The attachment holes 2h are situated on an outer
side of
the border 3 with respect to the filtrate vat 4, such that the attachment
holes 2h are not in
contact with filtrate within the filtrate vat, when in use.
Such an arrangement facilitates maintenance, as the attachment holes, through
which the
filter plate 2 is attached to the plate frame 9 are less like to be
contaminated form slurry,
filtrate ort other process fluids. Consequently, any fasteners used for
attaching the filter
plate to the plate frame are less likely to seize.
It should be noted that the first aspect of the present disclosure encompasses
any
combination of two or more embodiments, or variants thereof, in accordance
with the
above.
According to a second aspect of the present disclosure, a filter plate 2 for a
filter plate
assembly 1 of a horizontal plate and frame -type filter, such as a tower
press, is provided.
The filter plate 2 has a rigid plate-like body with a frame side 2a and a vat
side 2b. The
frame side 2a is intended to face towards a plate frame 9, on which the filter
plate is
supported, when in use, whereas the vat side 2b refers to the side of the
filter plate 2 on
which the filtrate vat 4 is formed, and is intended to face towards a filter
chamber formed
by the filter plate assembly together with an adjacent filter plate assembly
above.
The filter plate 2 comprises, on the chamber 2b side, a border 3 having at
least an inner
lateral wall 3a and an upper surface 3b. The border 3 is elevated for a
distance at least
from a portion of the filter plate 2 delimited within the border 3. Moreover,
the border 3 is
an integral part of the filter plate 2.
Preferably, but not necessarily, the filter plate 2 may have a vat area of
between 1,5 m2 ¨
9 m2. More preferably, but not necessarily, the filter plate 2 may have a vat
area of between
2,5 m2 ¨ 7 m2. Most preferably, but not necessarily, the filter plate 2 may
have a vat area
of between 2,5 m2 ¨ 7 m2. In the context of this disclosure, the vat area is
defined as the
area of the portion of the filter plate 2 delimited by the border 3, i.e. the
bottom of the filtrate
vat.
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Preferably, but not necessarily, the border, particularly the upper surface 3b
thereof, may
be elevated for a distance of at least 10 mm from the portion of the filter
plate 2 delimited
within the border. Preferably, but not necessarily, the border, particularly
the upper surface
3b thereof, may be elevated for a distance of no more than 40 mm from the
portion of the
filter plate 2 delimited within the border. For example, the border,
particularly the upper
surface 3b thereof, may be elevated for a distance of 15-20 mm from the
portion of the
filter plate 2 delimited within the border.
Preferably but not necessarily, the border 3 has a width of at least 15 mm.
Preferably, but
not necessarily, the border has a width of no more than 200 mm. For example,
the width
of the border may be between 75 mm - 100 mm. In the context of this
disclosure, the width
of the border 3 refers to a transverse dimension thereof parallel with the
planar bottom 5a.
Also, it should be noted, that the border may have different widths at
different parts of the
filter plate.
Particularly, a filtrate vat 4 is formed by the filter plate 2, such that the
inner lateral wall 3a
of the border forms a lateral wall of the filtrate vat 4, and a portion of the
filter plate delimited
by the border 3 forms a bottom of the filtrate vat 4. That is, a receptacle
for receiving filtrate
is formed by the shape of the filter plate 2 itself.
Preferably, but not necessarily, the filter plate 2 may have an average
material thickness
of between 8 mm ¨ 30 mm at the portion thereof delimited by the border 3.
In this way, the filter plate 2 may be constructed so as to provide a rigid
structure forming
the shape of the filtrate vat 4 being able to resist deformation due to
creeping.
Most suitably, the filter plate 2 is of a rigid material 5 able to resist
creeping. Examples of
such materials of the filter plate 2 include, but are not limited to, metals,
such as steel, FRP
(fibre-reinforce plastics) materials, such as reinforced composite materials
with a
thermoset or thermoplastic matrix, and thermoset materials.
In an embodiment according to the second aspect of the present disclosure, the
border 3
has an outer lateral wall 3c. In other words, the border 3 is also elevated
with respect to
an area of the filter plate 2 surrounding the border 3.
In an embodiment according to the second aspect of the present disclosure, a
gap 3d is
provided on the border 3, such that an outlet opening extending laterally
through the border
3 is formed, thereby providing a fluid drainage route from the filtrate vat 4.
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Preferably, but not necessarily, the one or more gaps 3d have a length of
between 150
mm ¨ 300 mm in the longitudinal direction of an associated side 2d, 2e, 2f, 2g
on which
the gap 3d is situated.
Preferably, but not necessarily, the gap 3d has a height corresponding to that
of the border
3.
Preferably, but not necessarily, on the vat side 2b of the filter plate 2, a
recessed portion
2c of the filter plate situated at the outlet opening is recessed with respect
the bottom of
the filtrate vat 4. Moreover, the vat liner 5 is spaced apart from the filter
plate 2 at the
recessed portion 2c in a direction transverse to the general planarity of the
filter plate 2.
Preferably, but not necessarily, the filter plate 2 is of a generally
rectangular shape having
a first flank side 2d and a second flank side 2e parallel to the first flank
side 2d, and a first
end side 2f and a second end side 2g parallel to the first end side 2f.
Moreover, the first
and second end sides 2f, 2g extend in a direction transverse to a direction in
which the
first and second flank sides 2d, 2e extend, and the first and second flank
sides 2d, 2e have
a length greater than that of the first and second end sides 2f, 2g.
In such a case, one or more gaps 3d of the border 3 are formed on either or
both of the
first flank side 2d and the second flank side 2e.
Preferably, but not necessarily, the length of the first and second flank
sides 2d, 2e is
between 1,5 ¨ 3 times of that of the first and second end sides 2f, 2g,
respectively
More preferably, one or more gaps 3d of the border 3 are formed in a corner
region
between a flank side 2d, 2e and an end side 2f, 2g.
More preferably, the filter plate comprises one or more lateral indentation
portions 2i
provided on either or both of the first flank side 2d and the second flank
side 2e. Such
lateral indentation portions 2i are arranged to circumvent suspension elements
and/or
support elements of a filter plate frame 9 on which the filter plate 2 is
supported.
Such an arrangement facilitates maintenance by allowing the filter plate 2 to
be removed
from a plate frame 9 on which it is supported without removing the plate frame
9 from the
filter apparatus.
The filter plate 2 may additionally comprise one or more lateral widening
portions 2j
provided on either or both of the first flank side 2d and the second flank
side 2e. The lateral
widening 2j portions are arranged between lateral indentation portions 2i
adjacent to the
widening portion 2j. Moreover, the lateral widening portions 2j are arranged
to laterally
overhang a filter plate frame 9 supporting the filter plate 2.
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Such an arrangement further facilitates maintenance by allowing the filter
plate 2 to be
lifted at the lateral widening portions 2j.
In an embodiment according to the second aspect of the present disclosure, the
filter plate
2 comprises a plurality of attachment holes 2h running along the periphery of
the filter plate
2 and extending therethrough. The attachment holes 2h are situated on an outer
side of
the border 3 with respect to the filtrate vat 4, such that the attachment
holes 2h are not in
contact with filtrate within the filtrate vat, when in use.
Such an arrangement facilitates maintenance, as the attachment holes, through
which the
filter plate 2 is attached to the plate frame 9 are less like to be
contaminated form slurry,
filtrate ort other process fluids. Consequently, any fasteners used for
attaching the filter
plate to the plate frame are less likely to seize.
It should be noted that the second aspect of the present disclosure
encompasses any
combination of two or more embodiments, or variants thereof, in accordance
with the
above.
According to a third aspect of the present disclosure, a vat liner 5 for a
filter plate assembly
1 of a horizontal plate and frame -type filter, such as a tower press, is
provided.
The vat liner 5 has a sheet -like body comprising a planar bottom portion 5a,
and a border
portion 5b. The border portion further comprises an inner lateral wall portion
extending
vertically from the planar bottom portion 5a, and an upper surface portion
extending
outwardly from the inner lateral wall portion in direction transverse thereto.
That is, the
upper surface portion is elevated from the planar bottom portion 5a.
Preferably, but not necessarily, the vat liner 5 may have a bottom area of
between 1,5 m2
¨ 9 m2. More preferably, but not necessarily, the vat liner 5 2 may have a
bottom area of
between 2,5 m2 ¨ 7 m2. Most preferably, but not necessarily, the vat liner 5
may have a
bottom area of between 2,5 m2¨ 7 m2. In the context of this disclosure, the
bottom area is
defined as the area of bottom surface (i.e. the surface intended to sit
against the filtrate
vat 4) of the vat liner 5 corresponding to the bottom portion 5b.
Preferably, but not necessarily, the upper surface portion of the border
portion 5b is parallel
with the planar bottom portion 5a.
Preferably, but not necessarily, the upper surface of the border portion 5b is
elevated at a
height of between 10mm - 40 mm from the planar bottom portion 5b. For example,
the
upper surface of the border portion 5b may be elevated at a height of 15mm
from the
planar bottom portion 5b.
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Preferably but not necessarily, the border portion 5b has a width of at least
15mm.
Preferably but not necessarily, the border portion 5b has a width of no more
than 200mm.
For example, the border portion 5b may have a width of between 75mm - 100mm.
In the
context of this disclosure, the width of the border portion 5b refers to a
transverse
dimension thereof parallel with the planar bottom 5a.
Preferably, but not necessarily, the vat liner 5 may have, at the bottom
portion 5a thereof,
a material thickness of between 1mm - 10mm, more preferably, but not
necessarily, of
between 2-5 mm. Preferably, but not necessarily, the vat liner 5 may have, at
the border
portion 5b thereof, a material thickness of between 1mm - lOmm, more
preferably, but not
necessarily, of between 2-5 mm.
In an embodiment according to the third aspect of the present disclosure, the
border
portion 5b further comprises an outer lateral wall portion extending from the
upper surface
portion. The outer lateral wall portion extends vertically with respect to the
planar bottom
portion 5a. In such an arrangement, a hollow trough Sc is formed on the vat
liner 5 by the
border portion 5b, running along the perimeter thereof.
In this kind of arrangement, when the vat liner 5 is nested in a corresponding
filtrate vat 4,
slurry or other process fluids are less likely to travel between the vat liner
5 and the filter
plate 5 all the way to the filtrate vat 4 or even the upper surface 3b of the
border 3, where
contamination may cause excess wear or even breakage under repetitive
compression,
as discussed above.
Furthermore, a more rigid structure of the vat liner 5 itself is achieved,
which facilitates
maintenance, as the vat liner 5 deforms less during installation and is easier
to be seated
in the filtrate vat 4.
In an embodiment according to the third aspect of the present disclosure, a
gap portion 5d
is formed on the border portion 5b, exhibiting a gap extending laterally
through the border
portion 5b. Moreover, the planar bottom portion 5a extends into the gap
portion.
In this arrangement, a fluid drainage route from the planar bottom portion 5a
is formed
laterally through the border portion 5b.
Preferably, but not necessarily, the one or more gap portions 5d have a length
of between
150 mm ¨ 300 mm in the longitudinal direction of an associated side portion 5e-
5h on
which the gap 5d is situated
Preferably, but not necessarily, if a hollow trough Sc is formed on the vat
liner 5, the trough
Sc is closed towards the gap portion (5d).
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In an embodiment according to the third aspect of the present disclosure, the
vat liner 5 is
of a generally rectangular shape having a first flank side portion 5e and a
second flank
side portion 5f parallel to the first flank side portion 5e, and a first end
side 5g portion and
a second end side portion 5h parallel to the first end side portion 5g.
The first and second end side portions 5g, 5h extend in a direction transverse
to a direction
in which the first and second flank side portions 5e, 5f extend. Moreover, the
first and
second flank side portions 5e, 5f have a length greater than that of the first
and second
end side portions 5g, 5h.
In such a configuration, one or more gap portions 5d of the border portion 5b
are suitably
formed on either or both of the first flank side portion 5e and the second
flank side portion
5f.
When a new vat liner is installed during maintenance, the vat liner 5 is
inserted in place
between adjacent filter plates either end side portion 5g, 5h first due to the
structure of the
associated filter press. In other words, the vat liner 5 is handled and
manipulated from the
first and second flank portions 5e, 5f. Providing the gap portions 5d at
either or both of the
first and second flank portions 5e, 5f (instead of the end side portions 5g,
5h) ensures that
an unbroken stiffened structure (i.e., trough Sc) is achieved at the end side
portions 5g,
5h, thereby improving the vat liners 5 ability to resist deformation during
installation, and
thereby facilitating maintenance.
Preferably, the length of the first and second flank side portions 5e, 5f is
1,5 ¨ 3 times that
of the first and second end side portions 5g, 5h.
Preferably, but not necessarily, one or more gap 5d portions of the border 5b
portion are
formed in a corner region between a flank side portion and an end side
portion.
It should be noted that the third aspect of the present disclosure encompasses
any
combination of two or more embodiments, or variants thereof, in accordance
with the
above.
Fig. 1 illustrates a plan view of a filter plate assembly according to an
embodiment of the
present invention. Particularly, Fig. 1 shows the filter plate assembly 1 as
seen from the
vat side 2b. The filter plate assembly has a filter plate 2 and a vat liner 5
placed on top the
filter plate 2. The filter plate 2 is of a rectangular shape having a first
flank side 2d, a second
flank side 2e, a first end side 2f and a second end side 2g.
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Outlet pieces 6 are placed at the first and second flank sides 2d, 2e at the
corner regions
between flank side 2d, 2e and the end sides 2f, 2g, where gaps 3d of the
border 3 and the
gap portions 5d of the vat liner 5 (covered by the outlet piece 6) are
exhibited.
A filtrate vat 4 is formed in the central are of the filter plate 2, delimited
by the border, and
is covered by the vat liner 5
The flank sides 2d, 2e have intended portions 2i, which are laterally recessed
with respect
to adjacent portions of the filter plate, and widening portions 2j, which
extend laterally
further with respect to their adjacent portions. The widening portions 2j are
provided
between intended portion 2i, although other configurations are foreseeable.
Attachment
holes 2h can be seen extending around the periphery of the filter plate 2.
Fig. 2 illustrates a cross-sectional cut view along the cut line illustrated
in Fig. 1 (i.e.,
running across the second flank side 2e). Fig. 2 illustrates the filter plate
2 being supported
on a plate frame 9. Moreover Fig. 2 better illustrates the border 3 of the
filter plate 2 having
an inner lateral wall 3a, top surface 2b and an outer lateral wall 3c. The vat
liner is seated
on the filter plate such that the border portion 5b receives the border 3 and
the bottom
portion 5a is seated in the area are delimited by the border (i.e. the
filtrate vat 4)
Fig. 3 illustrates a filter plate assembly 1 similar to that of Fig.1, without
outlet pieces 6,
and equipped with a filtrate vat 5, as seen as an exploded perspective view.
Fig. 3 also
illustrates how a grid 10 is to be received in the filtrate vat covered by the
vat liner 5. As
the Fig. 3 is shown as an exploded view, the border 3 of the filter plate 2 is
revealed along
with the gaps 3d, and the recessed portion 2c situated at the gaps 3d.
Fig. 4 illustrates the filter plate assembly of Fig. 3 as a plan view seen
from the vat side
2b. Fig. 4 shows a dashed line, along which the cross-sectional cut views of
Fig. 5 and
Fig. 6 are seen.
Fig. 5 illustrates the filter plate assembly of Fig. 3 as an exploded cross-
sectional cut view
along the dashed line illustrated in Fig. 4, whereas Fig. 6 is illustrated in
a non-exploded
view. These drawings clearly illustrate how the shape of the filtrate vat 4 is
formed by the
by the filter plate 2 and the border thereof, whereas the vat liner 5 merely
acts as a lining
following the shape of the actual filtrate vat 4. Moreover, these drawings
illustrate how the
vat liner 5 is tightly seated together with the filtrate vat 4 and the border
3, and how a grid
10 may be received in the filtrate vat 4, above the vat liner 5.
Fig. 7 illustrates the filter plate assembly of Fig. 1, as seen as a semi-
exploded perspective
view. Particularly, the vat liner 5 and the encircled outlet piece 6 haven
illustrated in a
displaced, unassembled configuration. Fig. 7 illustrated the vat liner 5, from
which the first
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flank side portion 5e, the second flank side portion 5f, the first end side
portion 5a and the
second end side portion can be identified forming a generally rectangular
shape of the vat
liner 5. Furthermore, the border portion 5b of the filtrate vat (and
particularly the chute 5c
formed thereunder) is closed towards the gap 3d.
Fig. 8 shows a detailed view of the outlet piece encircled in Fig. 7.
Particularly, Fig. 8
illustrates how the outlet piece is arranged with respect to the filter plate
2, and the vat
liner 5.
The base 7 of the outlet piece 6 is received in a seated manner in the
recessed portion 2b
of the outlet at the gap 3d of the border. Particularly, the base 7 is
situated between the
filter plate 2 and the vat liner 5, such that the vat liner 5 extends onto the
base 7. Fig. 8
also illustrates attachment members (i.e. screws, although other attachment
member may
be envisaged) with which the base 7 is attached to the filter plate 2.
Furthermore, the Fig.
8 shows the base having a recessed seat 7a against which the vat liner 5 is
placed, and
the recessed chute 7b extending from the recessed seat, slightly elevated
therefrom such
that the vat liner 5 extends up to the recessed chute 7b.
The lid 8 of the outlet piece is situated partially above the vat liner 5 and
is attachable to
the base 7, such that the vat liner 5 resides between the base 7 and the lid
8, and is
clamped therebetween in a sealed manner. It should be noted that the
attachment between
the lid 8 and the base 7 is situated on a portion of the outlet piece 6 onto
which the vat
liner 5 does not extend to, thereby separating the point of attachment between
the lid 8
and the base 7 from any filtrate running through the drainage route. Fig. 8
also illustrates
attachment members (i.e. screws, although other attachment member may be
envisaged)
with which the lid 8 is attached to the base 8.
Fig. 9 illustrates a detailed view of the outlet piece shown in Fig. 8 in an
assembled
configuration. It can also be seen from Fig. 9 that the lid 8 extends and
seals against the
border portion 5b of the vat liner 5, when attached to the base 7.
Fig. 10 is a plan view of the filter plate assembly 1 of Fig. 7, as seen from
the vat side 2b.
Fig. 11, illustrates an exploded cut view of the outlet piece denoted with the
number 6
along the dashed lined shown in Fig. 10, whereas Fig. 12 illustrates the same
in a non-
exploded configuration. Particularly Fig. 11 and Fig. 12 further illustrating
how the base 7
and lid 8 of the outlet piece 6 is arranged with respect to the filter plate 2
and the vat liner
S. Particularly the recessed seat 7a of the base 7 can be seen to be flush
with the filtrate
vat 4 and that the vat liner extends over the recessed seat 7a. Furthermore,
the ribs 8a of
the lid can be seen to press against the vat liner 5, thereby securely
clamping it in place
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and sealed against the recessed seat. Furthermore, the base 7 can be attached
to the
plate frame 9 through the filter plate 2.
LIST OF REFERENCE NUMERALS
1 filter plate assembly
2 filter plate
2a frame side
2b vat side
2c recessed portion
2d first flank side
2e second flank side
2f first end side
2g second end side
2h attachment holes
2i indented portion
2j widening portion
3 border
3a inner lateral wall
3b upper surface
3c outer lateral wall
3d gap
4 filtrate vat
5 vat liner
5a bottom portion
5b border portion
Sc trough
5d gap portion
5e first flank side portion
5f second flank side portion
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5g first end side portion
5h second end side portion
6 outlet piece
7 base
7a recessed seat
7b recessed chute
8 lid
8a rib
9 filter plate frame
10 filtrate vat
